JP6363351B2 - Sealing structure with gasket - Google Patents

Description

  The present invention relates to a structure in which sealing is performed by a gasket using a metal plate as a base material at a joint portion of a tubular body or a joint portion between a cylinder block and a cylinder head of an engine.

  As a sealing means for an engine exhaust manifold and exhaust pipe or a joint between an intake manifold and an intake pipe, etc., a gasket using a metal plate as a base material, that is, a metal gasket made of a single metal plate, or a surface of the metal gasket as an elastic body Metal-rubber composite gaskets coated with layers are widely known.

  That is, as shown in FIG. 5 (A), this type of gasket 100 is made of a single metal plate or a metal plate whose surface is covered with an elastic layer, and has inner and outer peripheral flange portions 101 and 102, and the flange portion 101, A full bead-like seal bead 103 is formed between the two parts 102 by embossing so that the cross-sectional shape is formed so as to form a symmetrical chevron on both sides of the top part 103a. As shown in FIG. 5 (B), the gasket 100 is interposed between the flanges 200 and 300 to be joined facing each other with the top portion 103a of the seal bead 103 facing the flange 200, By appropriately compressing the seal bead 103, the gas in the internal space S1 is prevented from leaking from between the flanges 200 and 300 to the external space S2, and intrusion of water or the like from the external space S2 to the internal space S1 is prevented. It is to prevent.

  In this type of gasket 100, the seal bead 103 has a top portion 103a that is in line contact with one flange 200, and the bottom portions 103b and 103c are in line contact with the flanges 200 and 300. In addition to increasing the seal surface pressure, it has an important function of obtaining a good close state by following the flatness of the flanges 200 and 300. As a typical conventional technique of a gasket having a metal plate as a base material and having a seal bead, the following patent document is known.

Japanese Patent Laid-Open No. 62-261755

By the way, in recent years, in order to improve fuel efficiency, engines and auxiliary machines, EVs (Electric Vehicles), HEVs (Hybrid Electric
Inverters for vehicles (hybrid vehicles) are becoming smaller and more powerful, and with this, the housing body and cover of the casing that houses the inverter unit must also be made smaller and lighter. The gasket interposed between the casing main body and the joint flange of the cover is also required to cope with low rigidity by reducing the thickness of the flange.

However, in the conventional sealing structure using the gasket 100, as shown in FIG. 5B, in the vicinity of each fastening portion by a plurality of bolts (not shown) for connecting the flanges 200 and 300, the seal bead is caused by the axial force of each bolt. 103, the top portion 103a is pressed against one flange 200 and the bottom portions 103b, 103c are pressed against the other flange 300. Further, as the seal bead 103 is compressed, the flange portions 101, 102 are the bottom portions of the seal bead 103. The portions 103 b and 103 c are deformed so as to jump up as fulcrums, and the edge portions 101 a and 102 a are in pressure contact with the flange 200. In this case, the sum of the loads due to the surface pressures P ₄ and P ₅ of the skirt portions 103 b and 103 c of the seal bead 103 with respect to the flange 300 is the top portion 103 a of the seal bead 103 with respect to the flange 200 and the edge portions 101 a of the flange portions 101 and 102. Since it is equal to the sum of the loads due to the surface pressures P ₁ , P ₂ , P ₃ of 102a, the reaction force against compression is large. The deformation of the flanges 200 and 300 increases between adjacent fastening portions (the opposing distance X between the flanges 200 and 300 increases), the axial force of the bolt is impaired, and the compression amount of the seal bead 103 of the gasket 100 is reduced. In other words, the surface pressure on the flanges 200 and 300 is insufficient, and sufficient sealing performance is not ensured. Have it.

  The present invention has been made in view of the above points, and the technical problem thereof is that of a seal bead caused by deformation of a mating flange between adjacent bolt fastening portions in a gasket sealing structure. The purpose is to suppress a decrease in sealing performance due to insufficient compression.

As means for effectively solving the above-mentioned technical problem, the invention of claim 1 is a pair of metal plates consisting of a single metal plate or a metal plate whose surface is covered with an elastic body layer, the edges facing each of the inner and outer peripheries. And a gasket having a full bead-shaped seal bead formed between the flanges are sandwiched between a pair of flanges fixed to each other by a plurality of bolts, and one of the pair of flanges is One of the flanges deformed so as to spring up with the bottom of the seal bead as the seal bead is compressed as the seal bead is pressed against the flange. In the sealing structure using a gasket, the one flange is not in contact with the other flange.

According to a second aspect of the present invention, there is provided the gasket sealing structure according to the first aspect, wherein the width of the surface of the one flange close to the top of the seal bead is made narrower than the width of the other flange. In this way, the other collar is not in contact.
According to a third aspect of the present invention, there is provided a gasket sealing structure according to the first or second aspect, wherein the one flange is a flange having a relatively low rigidity.

According to the sealing structure with a gasket according to the present invention, since one flange is not in contact with the other flange portion, the compression reaction force of the gasket is reduced, so that the flange between adjacent bolt fastening portions Therefore, sufficient surface pressure required for sealing can be ensured.

1 is a plan view showing a gasket as a single unit in a preferred embodiment of a sealing structure with a gasket according to the present invention; A preferred embodiment of a sealing structure with a gasket according to the present invention is shown by cutting at the position of line II-II in FIG. 1, (A) is a sectional view showing the gasket alone, (B), It is sectional drawing which shows the state which compressed the gasket between flanges. It is sectional drawing which shows other preferable embodiment of the sealing structure by the gasket which concerns on this invention. It is sectional drawing which shows other preferable embodiment of the sealing structure by the gasket which concerns on this invention. An example of the sealing structure by the gasket which concerns on a prior art is shown, (A) is sectional drawing which shows a gasket single-piece | unit, (B) is sectional drawing which shows the state which compressed the gasket between flanges.

  Hereinafter, a preferred embodiment of a sealing structure using a gasket according to the present invention will be described with reference to the drawings.

  First, the gasket denoted by reference numeral 1 in FIGS. 1 and 2 is made of a single metal plate or a metal plate whose surface is covered with an elastic layer, and extends in a frame shape corresponding to a flange described later. As shown in FIG. 2 (A), the gasket 1 has inner and outer flange portions 11 and 12 and chevron shapes whose cross-sectional shapes are symmetrical to each other on both sides of the top portion 13a by embossing between the flange portions 11 and 12. Bolt insertion holes 15 are formed in a plurality of projecting piece portions 14 formed at predetermined intervals on the flange portion 11 on the outer peripheral side. .

  As shown in FIG. 2 (B), the gasket 1 is interposed between the flanges 2 and 3 to be joined facing each other with the top portion 13a of the seal bead 13 facing the flange 2 side, By appropriately compressing the seal beads 13, the flanges 2 and 3 are brought into close contact with each other with a required sealing surface pressure, and gas in the internal space S1 is prevented from leaking from between the flanges 2 and 3 to the external space S2. This prevents water or the like from entering the internal space S1 from the external space S2.

  The flanges 2 and 3 are formed at, for example, a joint portion of a casing such as an inverter mounted on an EV or HEV, and have bolt insertion holes (not shown) corresponding to the respective bolt insertion holes 15 shown in FIG. A plurality of bolts (not shown) inserted through the bolt insertion holes are coupled to each other, and the gasket 1 is clamped between the flanges 2 and 3 by the axial force of the bolts.

  Of the flanges 2 and 3, the flange 2 having a relatively thin thickness t in the joining direction and a low rigidity has a narrower width than the other flange 3, and more specifically, the assembled state shown in FIG. 2, the inner peripheral edge 2 a of the flange 2 is positioned on the outer peripheral side of the edge 12 a of the flange 12 on the inner peripheral side of the gasket 1, and therefore the edge 12 a of the flange 12 is accompanied by the compression of the seal bead 13. Even if it is deformed, the flange 2 is kept in a non-contact state.

  That is, in the vicinity of each fastening portion (near each bolt insertion hole 15 shown in FIG. 1) by a plurality of bolts (not shown) that couple the flanges 2 and 3, the seal bead 13 has one top portion 13 a due to the axial force of each bolt. And the skirts 13 b and 13 c are pressed against the other flange 3, and the flanges 11 and 12 jump up with the skirts 13 b and 13 c of the seal bead 13 as fulcrums as the seal bead 13 is compressed. Accordingly, the edge portion 11a of the flange portion 11 on the outer peripheral side comes into pressure contact with the flange 2, but the inner peripheral edge 2a of the flange 2 is on the outer peripheral side than the edge portion 12a of the flange portion 12 on the inner peripheral side of the gasket 1. Therefore, the edge portion 12 a of the inner flange portion 12 deformed so as to jump up is not in contact with the flange 2.

For this reason, the sum of the loads due to the surface pressures P ₁₃ and P ₁₄ of the hem portions 13 b and 13 c of the seal bead 13 with respect to the flange 3 is the surface pressure P of the top portion 13 a of the seal bead 13 and the edge 11 a of the flange portion 11 with respect to the flange 2. _11, P ₁₂ equal to the sum of the load by, hence the gasket 1 is the same specification and the gasket 100 shown in FIG. 5 described above, and if the axial force of the bolt was also equal, the contact portion of the flange 2,3 Due to the decrease, the reaction force against compression is also smaller than that of the gasket 100 shown in FIG. 5, and the deformation of the flanges 2 and 3 between the adjacent bolt fastening portions is suppressed, that is, the axial force of the bolts is not easily damaged. Since the facing distance X is reduced as compared with FIG. 5 and the compression amount of the seal bead 13 is increased, a sufficient sealing performance can be ensured.

  In addition, when the width of the flange 2 is narrowed, there is a concern that the rigidity of the flange 2 is further decreased, and the axial force of the bolt is impaired between the adjacent bolt fastening portions. Even though the flange 2 is relatively thin in the joining direction, the flange t is sufficiently thick in comparison with the gasket 1, so that the rigidity is reduced by reducing the width. The influence of can be suppressed.

  3 and 4 show another embodiment of the sealing structure by the gasket according to the present invention. Among these, the embodiment shown in FIG. 3 is the inner peripheral portion of the flange 2 facing the flange 3. In addition, by forming the slope 2b so that the distance to the flange 3 increases toward the inner peripheral side, the bottom of the seal bead 13 is compressed in a state where the gasket 1 is sandwiched between the flanges 2 and 3. The edge portion 12a of the inner flange portion 12 deformed so as to jump up with the portion 13c as a fulcrum is maintained in a non-contact state with the flange 2.

  Further, in the embodiment shown in FIG. 4, the flange 2, 3 is formed by forming a stepped surface 2 c on the inner peripheral portion of the flange 2 facing the flange 3 so that the facing distance to the flange 3 is increased. In a state where the gasket 1 is sandwiched between them, the edge portion 12a of the inner peripheral side flange portion 12 deformed so as to jump up with the skirt portion 13c as a fulcrum with the compression of the seal bead 13 is not in contact with the flange 2 It is intended to be kept.

  3 and 4, the width of the flange 2 can be made equal to that of the other flange 3, so that a decrease in rigidity of the flange 2 can be suppressed minutely. Therefore, the deformation of the flanges 2 and 3 between the adjacent bolt fastening portions is further suppressed, so that a sufficient surface pressure necessary for sealing can be ensured.

DESCRIPTION OF SYMBOLS 1 Gasket 11, 12 ridge part 12a edge part 13 seal bead 2,3 flange 2a inner periphery 2b slope 2c level | step difference surface

Claims (3)

A gasket comprising a single metal plate or a metal plate whose surface is covered with an elastic layer, and having a pair of flange portions with edges facing the inner and outer peripheries and a full bead-shaped seal bead formed between the flange portions. Is sandwiched between a pair of flanges fixed to each other by a plurality of bolts, and one of the pair of flanges is in close contact with the top of the seal bead and the seal bead is compressed as the seal bead is compressed. A sealing structure with a gasket in which one of the flanges deformed so as to jump up with a skirt as a fulcrum is pressed against the one flange,
The gasket-sealed structure, wherein the one flange is not in contact with the other flange. The width of the surface of the one flange that is in close contact with the top of the seal bead is made smaller than the width of the other flange so as not to contact the other flange. Sealing structure with gasket.   The said one flange is a flange of the relatively low rigidity side, The sealing structure by the gasket of Claim 1 or 2 characterized by the above-mentioned.

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